Tuesday Jul 29, 2008

I've been asked several times how to make my example of javaagent which starts a firewall friendly JMX RMI Connector work on JDK 5. Well, here is how. However, beware of the catch: if you use SSL and want to connect with JConsole then you need to use Java 6 JConsole on the client side.

Tuesday Jun 03, 2008

No, rest assured - I have not conjured up some kind of new unfathomable hybrid beast from Dante's Seventh Hell... More prosaically, I have simply put together a small JavaScript slide show from some JMX 2.0 Namespace slides presented by Eamonn at
JavaOne 2008.

Tuesday May 06, 2008

Although it might not be a very good idea to define your management
model based on how it will be displayed by a given GUI, such as that
provided by JConsole or
VisualVM, I believe it is nonetheless
interesting to explore the various ways in which a complex type
such as a
Map<String,Integer> could be modeled and
exposed through an MXBean attribute.

Wednesday Jan 09, 2008

JMX is a wonderful tool to monitor and troubleshoot
running applications. The new JDK 6
Attach API makes it
very easy to attach to a running Java process, and start
a JMX agent that will expose monitoring and configuration
data to JMX consoles - like JConsole. However, there are
some situations where you wish to start a JMX agent on
demand, explore the monitoring data or diagnose the
probable cause of an observed problem, and then close
your JMX agent, leaving the application just how you
found it.

In this post, I will discuss a means by which you can
upload and start such a remotely stoppable JMX agent.
Here is how.

Monday Nov 12, 2007

This article exposes a proxying technique that can be used to
adapt between two different protocols: one that is used on the
server side, and one that we want to use on the client side.
More to the point,
this technique can be used to work around an annoying interoperation problem that can show up when exposing
Model MBeans through an IIOP connector.

Monday Oct 22, 2007

This post explains how you can configure your Java application to export
a single port using JMX RMI Connector Server over SSL. This is particularly
useful when your application is located behind a firewall, because you
will only need to let through a single port. However, using a single port
when SSL is enabled requires a little care, because it can only work if
the same RMI Socket Factories are used everywhere: indeed the same port
cannot be shared by two different RMI Socket Factories. So at the risk of
boring you, here is my third post on the subject.

Wednesday Sep 12, 2007

In my previous blog entry, I have talked about how to take
advantage of java agents in order to start a custom JMX
Connector in a Java application, without modifying the application.
This is particularly useful when you need to monitor Java
applications which are located behind a firewall. In that case,
it makes it possible to write a java agent that will start a
RMI connector configured in a firewall-friendly manner.
However, there's a catch. This is what this entry is about.

Can you simply explain how run jconsole on a client machine to connect to an unmodifiable applicaton that run on a server. One and only one port on the server is open though firewall for managing the application.